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מצאתי בגוגל את זה:
AxCrypt – An excellent free encryption utility that enables users to encrypt all files within a folder and not allow those files to be viewed unless a passphrase (password) is known.
WinCry – A freeware utility that enables your files to be encrypted, secure deletion, as well as other helpful methods of protecting your files.
Folder Guard – A commercial version of a password protection software that enables you to password protect files, folders, and other Windows resources.
Things to remember when encrypting or password protecting files and folders
There is no such thing as a 100% protected file. There are numerous tools, utilities, and instructions for how to break a lot of the encryption and passwords on files. However, the protection methods listed above will protect your files from the majority of users who may encounter them. If you're working with really sensitive data we suggest a commercial product for protecting your files and data.
Even though a file or folder may be password protected it still can be deleted (unless the program supports the ability to protect files from being deleted). Always remember to backup all your files, even those protected by passwords.
If you forget the password, unless you're willing to spend the time attempting to break it or pay someone else to break the password, all your file data will be lost. Unless you've made a backup of the non-password protected data.